“Specifically, when companies and corporate insiders make statements, they must act responsibly, including endeavouring to ensure the statements are not false or misleading and do not omit information a reasonable investor would consider important in making an investment decision.”

What did he say in the tweets?

The fraud allegation relates to his August tweet in which Mr Musk said he was considering taking electronic car maker Tesla off the stock market and into private ownership.

He wrote he had “funding secured” for the proposal, which would value Tesla at $420 per share. Shares in the company briefly rose after his announcement, but later fell again.